Yes, the 6106 is essentially a 5Y3. |
Sorlowski, it's the same tube. |
Bwhite,
I'm surprised you can hear differences in Ken Rad 6SN7 of different prints. I've literally handled over 500 of these tubes in my lifetime and can't discern any differences. I'm also surprised you prefer their midrange to Tung Sols. I have always found the KR midrange subpar for a 6SN7.
As for my Supratek (line stage only):
6SN7: I use primarily Tung Sol round plates, although I do swap in Sylvania 6SN7Ws, Raytheon (flat plates), Sylvania VT-231 (also 52 Bad Boys), and RCA grey glass on occassion. I'd skip the CV181/ECC32 if I were you. It's one of those "midrange" only tubes with anemic bass and attenuated highs. Fact is, it was never designed for audio purposes (it's an oscillator tube).
regulator: Visseaux 6L6G or Mullard EL37. While I like what the 350B does for the midrange, they aren't my cup of tea for the rest of the audio spectrum. 6F6 tubes are too lean (and a bit edgy) for my tastes and my system. KT66 didn't float my boat either (bass was subpar, soundstage was collasped).
rectifier: Philips metal base GZ34. Defintely not muddy sounding, and far more open then the later production black base Mullards (which I agree are more lush and syrupy). I've never tried 6106/5Y3 in this position, but I'll give it a shot this weekend. I'm surprised it works well in a circuit designed for GZ34.
Disclaimer: this is all, of course, personal opinion based on my system only. For full disclosure, I should also state that I was (and still kind of am) a tube seller. |
Hi Jazzdude,
I have both the carbon coated ST Visseaux and the tall GT glass version. I prefer the GTs by a small margin. If you want to sell any of your GT Visseaux, I'd love to buy them :-)
Tung Sol round plates stays in my 6SN7 position the vast majority of the time. However, I love the RCA grey glass midrange when I'm looking for something a bit more romantic and full. I'll swap in the Sylvania VT-231 or Bad Boys if I want more air.
-Len |
Hi Bwhite,
You've arrived at the erroneous conclusion that base prints mean something. They don't. It was not uncommon for base prints to be labelled months after the actual date of production, sometimes completely removed from the actual site of production (e.g. at distribution centers, where a lot of rebranding occurred). With the two notable exceptions of 5692 and W/WGT-suffixed tubes, there was no such thing as as a military-designed 6SN7 .... only different base prints for military-designATED 6SN7 (the US military used VT-231 as its numbering system, the British used CV1988, etc.). Yes, these tubes had to be made to milspec standards, but no, they weren't any different then their commercial-bound counterparts. There wasn't a factory churning out just military-designated tubes. Factories distributed the same exact tubes with different prints based on its intended destination. A Tung Sol 6SN7GT in commercial red and blue boxes is the exact same tube as a Tung Sol VT-231 in tan military boxes.
What are the three "flavors" of Ken Rad black glass you speak of? I've removed the glass from about half a dozen Ken Rads with various base prints (fwiw: I'd be happy to post pics of the internal constructions of some 6SN7s). Perhaps you've stumbled across some insight I overlooked. The only differences I've found is minor mica variations and grid posts constructed of different materials.
It's logical fallacy to assume that the differences you hear in tubes is due to vintage or material differences. Each and every 40s tube was hand-assembled by both skilled and not-so-skilled laymen. Thus, they're subject to variations due to build quality alone. Chances are, any differneces you heard were quality control related more then anything else.
To clarify, I am not doubting you hear differences. Some people simply have better auditory acuity. But you are the first person I know who can hear marked differences in Ken Rad black glass 6SN7/VT-231.
I currently use a Chardonnay. |
Bwhite,
How many of each "type" of KR have you auditioned? How can you rule out it wasn't a build quality issue due to a small sampling size? I've handled over a hundred of each type (just sold about 30 pairs of the Navy type in the last half year) and they sound the same to me as the other prints.
Tell us how you feel about the 350B, 6F6, KT66, Metal Base GZ34 and CV181/ECC32. I think everyone would benefit from unique opinions.
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Jazzdude,
The Tung Sol round plate is something special in all my applications (I have five gear that uses 6SN7s: Supratek, Audio Note, Korneff, Cary, and a Wheatfield headamp). It's always very open and smooth, with good linearity from top to bottom (no particular spectral emphasis unlike, for example, Ken Rads that emphasis bass). The Sylvania VT-231 are a bit more airy in the treble, but it lacks bass performance compared to the Tung Sol. The Syl VT-231 mids are also not quite as solid, although some might prefer its more delicate presentation. The RCA grey glass is a lot more euphonic and full sounding compared to the Tung Sol. RCA always romantizes the music in my systems, and I love it for that specific reason. |
Hey Jazzdude,
You're observation regarding the 6106 is exactly how I'd expect a 5Y3 will perform 5AR4-purposed circuit. Another thing I suspect is that it will distort more quickly.
FWIW, I'm burning in a Bendix 6106 right now. I'm going to give it a week and see how it works out. |
I'll cook them a bit more. All three Bendix I have are NOS/NIB, so I'll give them a fair shake by burning them a couple weeks longer. For 6106 users, how long does the tube life last? When called to do 5AR4 duty, the life should be significantly shortened.
For all intents and purposes, the 6106 is very much like the 5Y3 in electrical operation. Sure, it's indirectly heated and sound better then any 5Y3 I know, but it's still very similiar to a 5Y3 in regards to electrical function. Thus, I expect it to behave much like a 5Y3 in a 5AR4 application. It has nothing to do with the 6106 being the best 5Y3-type tube. It's still a 5Y3-type tube called to do 5AR4 duties. The analogy goes: throwing in a metal base GZ34 in to a 5U4G circuit doesn't mean it will perform well simply because the metal base GZ34 is the best of its kind.
In any case, I'll give it more time. FWIW: I, too, don't think the 350B will likely cause any damage in Suprateks (although it can happen). |
Bwhite,
You bring up a good point that new Supratek owners should take notice of. The Suprateks are ridiculously sensitive to microphony (not a good thing). I really don't know a linestage preamp that is more sensitive. You essentially need phono-grade quality tubes for line-grade application. If I had a gripe about the Supratek design, this would be it. And for this reason I hate selling 6SN7 to Supratek owners.
I agree the CV181 does not work in my preamp. I think you may have misread what I posted. It's a tube that I do not recommend (for the Supratek or for nearly all other 6SN7 applications).
I have Ken Rads with identical base prints - down to the alphanumeric date codes - but clearly different builds (tin versus copper grid posts, different mica varients, etc.). There might be audible differences as you say (I still can't hear marginal differences myself, much less "dramatic" ones). Whether you or I believe there are sonic differences or not, base print is a virtually useless criteria.
I also find the 350B midrange very neutral, which is what I love about this tube. In comparision, the EL34 and EL37 midrange is a touch bloomy and warm. The 350B sounds fast and accurate. It does not, however, sound powerful IME. There is a leaness to the presentation that (reminds me of KT66 tubes) compared to EL37 and 6L6 tubes. The 6F6 also has possesses this leaness, and it too is very fast (faster even) and "accurate" like the 350B. |
Fiddler,
IME, the Sylvania Bad Boys is comparitively "dry" sounding versus the Tung Sol's more liquid, "wet" sound. For clarification's sake, I am not using the adjective "dry" with any negative connotation. It's a matter of perference. I like the Bad Boys; they've got better control of attack and decay then the Tung Sols, and the Sylvania 6SN7GT '52 have more spatial seperate and thus sound slightly more resolved. The high frequencies have an uncanny air to them. However, the Tung Sols simply reproduces harmonics that is extremely beautiful to my ears .... a bit more full and palpable. And they sound more balanced from top to bottom. |
It's been about a week of burning in the 6106. It definitely sounds different then the GZ34, but not better in my system. I can only arrive at the conclusion that one's opinion of this configuration is very system specific. With my Art Audio Jotas and Merlin VSM, the 6106+350B combo was too lean. Swapping in my Audio Note speakers (inherently colored, full, warm speakers), the 6106+350B was better.
I'm going back to my metal base GZ34. Besides the fact I prefer the sonics, I prefer to run my gear with tubes it's designed for. I've had transformers/power supplies (in other gear) damaged when substituting non-equivalents (e.g. ECC32 in 6SN7), so I have a inclination to play it safe these days. FYI: this damage is rarely immediately apparent, but rather it manifests itself over long durations (e.g. years). Just be careful when running your gear beyond tolerance. |
It's the same tube. "Red Bank" refers to a specific Bendix manufacturing division/plant (located in New Jersey), not any cosmetic differences. |
These companies simply underwent numerous brand and operational name changes through the years under different ownerships. MWT (Marconi Wireless Telegraph), Osram (Edison General Electric), Genelec (General Electric), GEC (General Electric Company), Marconi Valve, Marconi Osram, English Electric, et al (I'm sure I missed a few) are all essentially the same company at different stages during history.
GEC-branded KT66 came in both clear and grey glass, black or brown base. The reason why most Genelec-branded KT66s are clear glass is because this was a marketing name used in later years (when only clear glass KT66s were produced). Similiar, the reason why ST "coke" bottled KT66s were mostly labelled as MWT or Osram is because these were developed and sold during the earlier years. Although brand names aren't an abosolute indicator of vintage, it can give some general insights as to when the tubes were sold. |
The Marconi companies were named after their famous founder, Guglielmo Marconi. He was an Italy, but he established and operated his company in England.
The grey glass version is usually regarded as tubier sounding: a bit sweeter, richer, and warmer. The KT66 did go through a few changes with it's oxide plate coating, which probably explains the differences in sound (likely has little or nothing to do with the graphic coating on the glass). |
I am assuming the Supratek can handle the 6H30. While often touted as a 6922 variant, it really is a much more demanding tube and should never be substituted into a 6922 application (though it's often safe to sub 6922 in place of gear designed for 6H30).
The 6H30 you should seek out is the 6H30P-DR. It's the premium version of this soviet tube, built with much better parts and tighter specifications. thetubestore.com has them in stock last time I checked. |
A dissenting opinion on 76. I'm not a big fan. I have many pairs for my personal use and have sold quite a few in the past, but in terms of sonic attributes, I'd much rather use 6SN7 then 76 tubes myself. |
